Spring-Assisted Hinged Cranioplasty for Nonsyndromic Unicoronal Synostosis: A Surgical Technique

Objective: Unicoronal craniosynostosis is the premature fusion of one coronal suture resulting in supra-orbital, midface and skull base asymmetry. While spring-assisted cranioplasty is known to be effective for sagittal craniosynostosis, there is little reported regarding its use in unicoronal synostosis. The purpose of this study is to report a new technique and experience with spring-assisted hinged cranioplasty for unicoronal synostosis. Methods: Demographic data, complications, and hospital course for 5 consecutive patients that underwent spring-assisted cranioplasty for nonsyndromic unicoronal synostosis since 2022 at our institution were reviewed. The surgical technique, which utilizes a fronto-orbital hinged cranioplasty with removal of the fused suture and placement of springs, is described. Results: Five patients were included, with an average age at time of cranioplasty of 6.4 months. There were 3 complications, 1 superficial infection treated with oral antibiotics and 2 patients requiring return to OR for removal of vicryl suture found to be inhibiting spring expansion. Conclusion: We describe a surgical technique utilizing a hinged cranioplasty design for spring-assisted correction of unicoronal synostosis. The theorized mechanism of correction employs dynamic remodeling, which provides some correction for skull base and midface deformities with reduced reliance on caregiver compliance compared to helmet therapy or distraction.